Display

ABSTRACT

A display includes a display surface, an electroluminescent panel, which has a plurality of electroluminescent elements, and a liquid crystal panel, which has a plurality of liquid crystal elements. The liquid crystal panel and the electroluminescent panel overlaps each other in the front and rear direction of the display. The electroluminescent elements and the liquid crystal elements are aligned with each other in the front and rear direction of the display. In the display, at least one of the electroluminescent elements and the liquid crystal elements function as pixels to show an image on the display surface. Therefore, the display can show an image in the appropriate manner in accordance with an environment.

BACKGROUND OF THE INVENTION

This application claims priority and is a divisional of U.S. patentapplication Ser. No. 10/356,232 filed on Jan. 31, 2003.

The present invention relates to a display that is a combination of aliquid crystal panel and an electroluminescent panel.

Liquid crystal displays are classified into reflective type andtransmissive type depending on the lighting system. A transmissiveliquid crystal display has a higher image quality than a reflectiveliquid crystal display but has a drawback that the power consumption isgreat. On the other hand, a reflective liquid crystal display has smallpower consumption but has a drawback that the image quality isinsufficient under an environment where the lighting intensity is notenough.

An organic electroluminescent display has been proposed as a displayhaving superior display performance. However, the organicelectroluminescent display also has a drawback that the image quality isinsufficient under an environment where the lighting intensity is highsuch as the outdoors.

Japanese Laid-Open Patent Publication No. 2000-267097 discloses adisplay that is a combination of a liquid crystal panel and an organicelectroluminescent panel. However, the organic electroluminescent panelonly functions as a front light.

SUMMARY OF THE INVENTION

Accordingly, it is an objective of the present invention to provide adisplay that functions in accordance with the environment.

To achieve the above objective, the present invention provides adisplay, which includes a display surface, an electroluminescent panel,and a liquid crystal panel. The electroluminescent panel has a pluralityof electroluminescent elements. The liquid crystal panel overlaps theelectroluminescent panel in a front and rear direction of the display.The liquid crystal panel includes a plurality of liquid crystalelements. The electroluminescent elements and the liquid crystalelements are aligned with each other in the front and rear direction ofthe display. At least one of the electroluminescent elements and theliquid crystal elements function as pixels to show an image on thedisplay surface.

Other aspects and advantages of the invention will become apparent fromthe following description, taken in conjunction with the accompanyingdrawings, illustrating by way of example the principles of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with objects and advantages thereof, may best beunderstood by reference to the following description of the presentlypreferred embodiments together with the accompanying drawings in which:

FIG. 1 is a partial schematic cross-sectional view illustrating adisplay according to a first embodiment of the present invention;

FIG. 2 is a partial cross-sectional view explaining the operation of adisplay shown in FIG. 1 in a first operation mode;

FIG. 3 is a partial cross-sectional view explaining the operation of adisplay shown in FIG. 1 in a second operation mode;

FIG. 4 is a partial cross-sectional view explaining the operation of adisplay shown in FIG. 1 in a third operation mode;

FIG. 5 is a partial schematic cross-sectional view illustrating adisplay according to a second embodiment of the present invention;

FIG. 6 is a partial cross-sectional view explaining the operation of adisplay shown in FIG. 5 in a fourth operation mode;

FIG. 7 is a partial cross-sectional view explaining the operation of adisplay shown in FIG. 5 in a fifth operation mode; and

FIG. 8 is a partial cross-sectional view explaining the operation of adisplay shown in FIG. 5 in a sixth operation mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment of the present invention will now be described withreference to FIGS. 1 to 4.

As shown in FIG. 1, a display 11 according to the first embodiment hasan electroluminescent panel 13 and a liquid crystal panel 14, which islocated at the rear of the electroluminescent panel 13. In the firstembodiment, the front surface (lower surface as viewed in FIG. 1) of theelectroluminescent panel 13 serves as a display surface. The drivesystems of the electroluminescent panel 13 and the liquid crystal panel14 are both passive matrix systems.

The electroluminescent panel 13 has a first substrate 12, which is madeof glass and transparent. Color filters 15 are located on the surface ofthe first substrate 12 that faces the liquid crystal panel 14 to form astripe. The color filters 15 extend parallel to each other. Atransparent planarizing layer 16 covers the color filters 15.

First anodes 17 are located on the surface of the planarizing layer 16that faces the liquid crystal panel 14 to form a stripe. The firstanodes 17 extend parallel to each other and the lengthwise direction ofthe color filters 15. Each first anode 17 is aligned with one of thecolor filters 15 in the front and rear direction of the display 11(vertical direction as viewed in FIG. 1). The first anodes 17 are madeof transparent material such as indium-tin oxide (ITO), which passeslight.

A thin-film organic layer 18 is located on the surfaces of the firstanodes 17 that face the liquid crystal panel 14. The organic layer 18 ismade of organic electroluminescent material and transparent. Morespecifically, the organic layer 18 consists of a hole injection layer, ahole transport layer, a light-emitting layer, and an electron transportlayer, which are arranged from the first anodes 17 toward the liquidcrystal panel 14 in this order.

First cathodes 19 are located on the surface of the organic layer 18that faces the liquid crystal panel 14. The first cathodes 19 extendparallel to each other and perpendicular to the first anodes 17. Thefirst cathodes 19 are formed of transparent material such as indium-tinoxide (ITO), which passes light.

A transparent sealing film 20 is located on the surfaces of the firstcathodes 19 that face the liquid crystal panel 14. The sealing film 20isolates the organic layer 18 from the outside. A polarizing plate 28 islocated on the surface of the sealing film 20 that faces the liquidcrystal panel 14.

Parts of the organic layer 18 that are sandwiched between the firstanodes 17 and the first cathodes 19 correspond to electroluminescentelements (organic light-emitting diode) G1. In other words, eachelectroluminescent element G1 is formed at the intersecting portionbetween one of the first anodes 17 and one of the first cathodes 19. Theelectroluminescent elements G1 are arranged in a matrix. Eachelectroluminescent element G1 overlaps one of the color filters 15 inthe front and rear direction of the display 11.

Each electroluminescent element G1 is driven in accordance with anelectric field that acts on the electroluminescent element G1 by theapplication of D.C. voltage to the corresponding first anode 17 and thecorresponding first cathode 19. When a predetermined voltage is appliedto one of the first anodes 17 and one of the first cathodes 19, anelectric field having the intensity that corresponds to the appliedvoltage acts on the corresponding electroluminescent element G1, whichcauses the electroluminescent element G1 to emit white light.

Voltage is applied to the first anodes 17 and the first cathodes 19 by adrive apparatus, which is not shown. The drive apparatus is controlledby a controller, which is not shown.

The liquid crystal panel 14 has a second substrate 21 and a thirdsubstrate 23, which face each other with a space formed in between. Thesecond substrate 21 is made of glass and transparent. The secondsubstrate 21 is located on the polarizing plate 28 and is closer to theelectroluminescent panel 13 than the third substrate 23.

A sealing material 22 and a liquid crystal 24 are located between thesecond substrate 21 and the third substrate 23. The sealing material 22surrounds the periphery of the liquid crystal 24 to isolate the liquidcrystal 24 from the outside.

Second cathodes 25 are located on the surface of the second substrate 21that faces the third substrate 23 to form a stripe. The second cathodes25 extend parallel to each other. Each second cathode 25 is aligned withone of the first cathodes 19 of the electroluminescent panel 13 in thefront and rear direction of the display 11. The second cathodes 25 aremade of transparent material such as indium-tin oxide (ITO), whichpasses light.

Second anodes 26 are located on the surface of the third substrate 23that faces the second substrate 21 to form a stripe. The second anodes26 extend parallel to each other and perpendicular to the secondcathodes 25. Each second anode 26 is aligned with one of the firstanodes 17 of the electroluminescent panel 13 in the front and reardirection of the display 11. The second anodes 26 are made of opaquematerial such as metal (for example, aluminum) and reflect light.

Portions of the liquid crystal 24 sandwiched between the second cathodes25 and the second anodes 26 correspond to liquid crystal elements G2. Inother words, each liquid crystal element G2 is formed at an intersectingportion between one of the second cathodes 25 and one of the secondanodes 26. The liquid crystal elements G2 are arranged in a matrix. Eachliquid crystal element G2 is aligned with one of the electroluminescentelements G1 and overlaps one of the color filters 15 in the front andrear direction of the display 11.

Each liquid crystal element G2 is driven in accordance with an electricfield that acts on the liquid crystal element G2 by the application ofD.C. voltage to the corresponding second cathode 25 and thecorresponding second anode 26. When a predetermined voltage is appliedto one of the second cathodes 25 and one of the second anodes 26, anelectric field having the intensity that corresponds to the appliedvoltage acts on the corresponding liquid crystal element G2, whichcauses the arrangement of the liquid crystal molecules of the liquidcrystal element G2 to vary in a reversible manner. The liquid crystalelement G2 passes light when the electric field is not applied, andblocks light when the electric field is applied. In the drawing, theliquid crystal elements G2 that are in a light-transmitting state areshown in white solid color and liquid crystal elements G2 that are in alight-blocking state are shown in stripes.

Voltage is applied to the second cathodes 25 and the second anodes 26 bya drive apparatus, which is not shown. The operation of the driveapparatus is controlled by a controller, which is not shown.

Operations of the display 11 will be described with reference to FIGS. 2to 4.

FIG. 2 shows a first operation mode (EL operation mode) of the display11, in which the electroluminescent elements G1 function as pixels. Inthe first operation mode, the display 11 utilizes light emitted from theelectroluminescent elements G1 as a light source.

In the first operation mode, a predetermined voltage is selectivelyapplied to each of the first anodes 17 and each of the first cathodes19. The electroluminescent element G1 that is located at theintersecting portion between the first anode 17 and the first cathode 19to which voltage is applied emits white light. The light emitted fromthe electroluminescent element G1 is radiated toward the color filter 15that overlaps the electroluminescent element G1 in the front and reardirection of the display 11. The light emitted from theelectroluminescent element G1 is converted into either red, green, orblue by the color filter 15, and is sent out from the display surface(see arrows described in chain-double dashed lines shown in FIG. 2).

When the display 11 is operating in the first operation mode, the liquidcrystal elements G2 may be maintained in either the light-transmittingstate or the light-blocking state. When the liquid crystal elements G2are maintained in the light-blocking state, that is, when apredetermined voltage is applied to all the second cathodes 25 and allthe second anodes 26, the display 11 displays a high contrast image onthe display surface.

FIG. 3 shows a second operation mode (liquid crystal operation mode) ofthe display 11, in which the liquid crystal elements G2 function aspixels. In the second operation mode, the display 11 utilizes outsidelight as a light source.

In the second operation mode, a predetermined voltage is selectivelyapplied to each of the second cathodes 25 and each of the second anodes26. The liquid crystal element G2 that is located at the intersectingportion between the second cathode 25 and the second anode 26 to whichvoltage is applied is switched to block light.

The outside light that enters the display 11 via the display surface istransmitted through the liquid crystal 24 only at portions correspondingto the liquid crystal elements G2 that are in the light-transmittingstate. The outside light that has passed through the liquid crystal 24reaches the second anodes 26 and is reflected by the second anodes 26.The reflected light is converted into either red, green, or blue by thecolor filters 15 and sent out from the display surface (see arrowsdescribed in heavy lines shown in FIG. 3).

When the display 11 is operating in the second operation mode, theelectroluminescent elements G1 are kept in a non-light-emitting state.That is, no voltage is applied to the first anodes 17 and the firstcathodes 19.

FIG. 4 shows a third operation mode of the display 11, in which bothelectroluminescent elements G1 and the liquid crystal elements G2function as pixels. In the third operation mode, the display 11 utilizesboth the light emitted from the electroluminescent elements G1 and theoutside light as a light source.

In the third operation mode, a predetermined voltage is selectivelyapplied to each of the first anodes 17 and each of the first cathodes19. Simultaneously, a predetermined voltage is applied to the secondcathode 25 and the second anode 26 that correspond to the liquid crystalelement G2 aligned with the electroluminescent element G1 that is in thenon-light-emitting state in the front and rear direction of the display11.

The outside light that enters the display 11 via the display surface andlight that leaks toward the rear side of the display 11 (upward asviewed in FIG. 4) from the electroluminescent elements G1 aretransmitted through the liquid crystal 24 at only the portionscorresponding to the liquid crystal elements G2 that are in thelight-transmitting state. The lights then reach the second anodes 26 andare reflected by the second anodes 26. The reflected light and the lightemitted from the electroluminescent elements G1 are converted intoeither red, green, or blue at the color filters 15 and sent out from thedisplay surface (see arrows described in chain double-dashed lines andheavy lines in FIG. 4).

The present invention provides the following advantages.

In the first operation mode, the display 11 utilizes light emitted fromthe electroluminescent elements G1 as a light source. Therefore, thedisplay 11 indicates an image that is easily visible on the displaysurface although the display 11 is used under an environment where thelighting intensity is insufficient such as the indoors or at night.

In the second operation mode, the display 11 utilizes the outside lightas a light source. Therefore, the display 11 reduces power consumptionunder an environment where the lighting intensity is sufficient such asthe outdoors.

In the third operation mode, the display 11 utilizes both the lightemitted from the electroluminescent elements G1 and the outside light asa light source. Therefore, the display 11 shows a bright andhigh-contrast image that is easily visible on the display surface underan environment where the lighting intensity is high.

The electroluminescent elements G1 are aligned with the liquid crystalelements G2 in the front and rear direction of the display 11.Therefore, when operated in the third operation mode, the display 11shows a bright and high-contrast image on the display surface using boththe light emitted from the electroluminescent elements G1 and theoutside light as a light source.

Since the display 11 has the color filters 15, the display 11 shows acolored image on the display surface.

The display 11 is easily manufactured by overlapping theelectroluminescent panel 13 with the liquid crystal panel 14.

The electroluminescent panel 13 is located closer to the display surfacethan the liquid crystal panel 14. This reduces the amount of lightdecreased from when the light is emitted from the electroluminescentelements G1 until when the light reaches the display surface. Thus, thedisplay 11 is particularly suitable for purposes that utilize the lightemitted from the electroluminescent elements G1 as a light source. Thatis, the display 11 is particularly suitable for usage under anenvironment where the lighting intensity is insufficient such as theindoors or at night.

A second embodiment of the present invention will now be described withreference to FIGS. 5 to 8. Like or the same reference numerals are givento those components that are like or the same as the correspondingcomponents of the first embodiment.

As shown in FIG. 5, the display 11 according to the second embodimenthas the liquid crystal panel 14 and the electroluminescent panel 13,which is located at the rear of the liquid crystal panel 14. In thesecond embodiment, the front surface (lower surface as viewed in FIG. 5)of the liquid crystal panel 14 serves as a display surface. The drivesystems of the electroluminescent panel 13 and the liquid crystal panel14 are both passive matrix systems.

The liquid crystal panel 14 has the second substrate 21 and the thirdsubstrate 23, which face each other with a space formed in between. Thesecond substrate 21 and the third substrate 23 are adhered to each otherby the sealing material 22. The second substrate 21 and the thirdsubstrate 23 are made of glass and transparent. The third substrate 23is located closer to the electroluminescent panel 13 than the secondsubstrate 21.

The color filters 15 are located on the surface of the second substrate21 that faces the third substrate 23 to form a stripe. The color filters15 extend parallel to each other. The transparent planarizing layer 16covers the color filters 15.

The second anodes 26 are located on the planarizing layer 16 that facesthe third substrate 23 to form a stripe. The second anodes 26 extendparallel to each other and the lengthwise direction of the color filters15. Each second anode 26 is aligned with one of the color filters 15 inthe front and rear direction of the display 11 (vertical direction asviewed in FIG. 5). The second anodes 26 are made of transparent materialsuch as indium-tin oxide (ITO), which passes light.

The second cathodes 25 are located on the surface of the third substrate23 that faces the second substrate 21 to form a stripe. The secondcathodes 25 extend parallel to each other and perpendicular to thesecond anodes 26. The second cathodes 25 are formed of transparentmaterial such as indium-tin oxide (ITO), which passes light.

The liquid crystal 24 is located between the second cathodes 25 and thesecond anodes 26. The sealing material 22 surrounds the periphery of theliquid crystal 24 to isolate the liquid crystal 24 from the outside.

The polarizing plate 28 is located on the surface of the secondsubstrate 21 that faces the front side (downward as viewed in FIG. 5) ofthe display 11. Another polarizing plate 29 is located on the surface ofthe third substrate 23 that faces the electroluminescent panel 13.

Parts of the liquid crystal 24 that are sandwiched between the secondcathodes 25 and the second anodes 26 correspond to the liquid crystalelements G2. The liquid crystal elements G2 are arranged in a matrix.Each liquid crystal element G2 overlaps one of the color filters 15 inthe front and rear direction of the display 11.

The electroluminescent panel 13 has the first substrate 12. The firstsubstrate 12 is made of glass and transparent. The first anodes 17 arelocated on the surface of the first substrate 12 that faces the rearside (upward as viewed in FIG. 5) of the display 11 to form a stripe.The first anodes 17 extend parallel to each other. Each first anode 17is aligned with one of the second anodes 26 of the liquid crystal panel14 in the front and rear direction of the display 11. The first anodes17 are made of transparent material such as indium-tin oxide (ITO),which passes light.

The thin-film organic layer 18 is located on the surfaces of the firstanodes 17 that face the rear side of the display 11. The organic layer18 is made of organic electroluminescent material and transparent. Theorganic layer 18 consists of a hole injection layer, a hole transportlayer, a light-emitting layer, and an electron transport layer, whichare arranged from the first anodes 17 toward the rear side of thedisplay 11 in this order.

The first cathodes 19 are located on the surface of the organic layer 18that faces the rear side of the display 11. The first cathodes 19 extendparallel to each other and perpendicular to the first anodes 17. Eachfirst cathode 19 is aligned with one of the second cathodes 25 in thefront and rear direction of the display 11. The first cathodes 19 aremade of opaque material such as metal (for example, aluminum) andreflect light.

The sealing film 20 is located on the surfaces of the first cathodes 19that face the rear side of the display 11. The sealing film 20 isolatesthe organic layer 18 from the outside.

Parts of the organic layer 18 that are sandwiched between the firstanodes 17 and the first cathodes 19 correspond to the electroluminescentelements G1. The electroluminescent elements G1 are arranged in amatrix. Each electroluminescent element G1 is aligned with one of theliquid crystal elements G2 and overlaps one of the color filters 15 inthe front and rear direction of the display 11.

Operations of the display 11 according to the second embodiment will bedescribed with reference to FIGS. 6 to 8.

FIG. 6 shows a fourth operation mode (liquid crystal operation mode) ofthe display 11, in which the liquid crystal elements G2 function aspixels. In the fourth operation mode, the display 11 utilizes theoutside light as a light source.

In the fourth operation mode, a predetermined voltage is selectivelyapplied to each of the second cathodes 25 and each of the second anodes26. The liquid crystal element G2 that is located at the intersectingportion of the second cathode 25 and the second anode 26 to which thevoltage is applied is switched to block light.

The outside light that enters the display 11 via the display surface istransmitted through the liquid crystal 24 at only the portionscorresponding to the liquid crystal elements G2 that are in thelight-transmitting state. The outside light then reaches the firstcathodes 19 and are reflected by the first cathodes 19. The reflectedlight is converted into either red, green, or blue at the color filters15 and sent out from the display surface (see arrows indicated by heavylines in FIG. 6).

When the display 11 is operating in the fourth operation mode, theelectroluminescent elements G1 are maintained in the non-light-emittingstate. That is, no voltage is applied to the first anodes 17 and thefirst cathodes 19.

FIG. 7 shows a fifth operation mode of the display 11. In the fifthoperation mode, the liquid crystal elements G2 function as pixels andthe electroluminescent elements G1 function as a light source for thebacklight that always emit light.

In the fifth operation mode, a predetermined voltage is applied to allthe first anodes 17 and all the first cathodes 19. As a result, all theelectroluminescent elements G1 emits white light. Therefore, the lightemitted from the electroluminescent elements G1 is radiated at all theliquid crystal elements G2 (see arrows described in chain double-dashedlines shown in FIG. 7). The liquid crystal panel 14 is operated in thesame manner as the fourth operation mode.

On the other hand, the outside light that enters the display 11 via thedisplay surface is transmitted through the liquid crystal 24 at only theportions corresponding to the liquid crystal elements G2 that are in thelight-transmitting state, and reaches the first cathodes 19. The lightthat reached the first cathodes 19 is reflected by the first cathodes19. The reflected light is converted into either red, green, or blue atthe color filters 15 together with the light emitted from theelectroluminescent elements G1 toward the color filters 15, and sent outfrom the display surface (see arrows indicated by heavy lines in FIG.7).

FIG. 8 illustrates a sixth operation mode of the display 11. In thesixth operation mode, the liquid crystal elements G2 function as pixelsand the electroluminescent elements G1 function as a light source forthe backlight that emits light as required. In other words, theelectroluminescent elements G1 and the liquid crystal elements G2 bothfunction as pixels.

In the sixth operation mode, voltage is selectively applied to each ofthe first anodes 17 and each of the first cathodes 19. Simultaneously, apredetermined voltage is applied to the second cathode 25 and the secondanode 26 that correspond to the liquid crystal element G2 that isaligned with the electroluminescent element G1 that is in thenon-light-emitting state in the front and rear direction of the display11. Thus, the light emitted from the electroluminescent element G1 isonly radiated at the liquid crystal elements G2 that are in thelight-transmitting state (see arrows described in chain double-dashedlines in FIG. 8).

The outside light that enters the display 11 from the display surface istransmitted through the liquid crystal 24 at only the portionscorresponding to the liquid crystal elements G2 that are in thelight-transmitting state, and reaches the first cathodes 19. The lightthat reached the first cathodes 19 is reflected by the first cathodes19. The reflected light is converted into either red, green, or blue atthe color filters 15 together with the light emitted from theelectroluminescent elements G1 toward the color filters 15 and sent outfrom the display surface (see arrows indicated by heavy lines in FIG.8).

The second embodiment provides the following advantages.

In the fourth operation mode, the display 11 utilizes the outside lightas a light source. Therefore, the display 11 has reduced powerconsumption under an environment where the lighting intensity issufficient such as the outdoors.

In the fifth and sixth operation modes, the display 11 utilizes thelight emitted from the electroluminescent elements G1 as a light source.Therefore, the display 11 shows a bright image that is easily visible onthe display surface under an environment where the lighting intensity isinsufficient such as the indoors or at night.

In the sixth operation mode, each electroluminescent element G1 emitslight as required in accordance with the corresponding liquid crystalelement G2. Therefore, the power consumption is reduced as compared tothe fifth operation mode.

The electroluminescent elements G1 and the liquid crystal elements G2are aligned with each other in the front and rear direction of thedisplay 11. Therefore, in the fifth and sixth operation modes, eachelectroluminescent element G1 efficiently radiates light at thecorresponding liquid crystal element G2.

It should be apparent to those skilled in the art that the presentinvention may be embodied in many other specific forms without departingfrom the spirit or scope of the invention. Particularly, it should beunderstood that the invention may be embodied in the following forms.

The electroluminescent elements G1 may be replaced withelectroluminescent elements formed of inorganic electroluminescentmaterial.

The electroluminescent panel 13 may be replaced with anelectroluminescent panel that is driven by a system other than thepassive matrix system, such as the active matrix system.

The liquid crystal panel 14 may be replaced with a liquid crystal panelthat is driven by a system other than the passive matrix system, such asthe active matrix system.

The electroluminescent elements G1 and the liquid crystal elements G2need not be aligned with each other entirely in the front and reardirection of the display 11 as long as the electroluminescent elementsG1 and the liquid crystal elements G2 are partially aligned with eachother.

In the second embodiment, an image may be shown on the display surfaceby using the electroluminescent elements G1 as pixels as in the firstoperation mode of the first embodiment. In this case, no voltage isapplied to the second cathodes 25 and the second anodes 26 so that allthe liquid crystal elements G2 are in the light-transmitting state.

The display 11 may be designed to be able to adjust the brightness ofeach pixel. In this case, the display 11 can show a gray level image onthe display surface.

Therefore, the present examples and embodiments are to be considered asillustrative and not restrictive and the invention is not to be limitedto the details given herein, but may be modified within the scope andequivalence of the appended claims.

1. A display, comprising: a display surface; an electroluminescentpanel, the electroluminescent panel having a plurality ofelectroluminescent elements; and a liquid crystal panel, which overlapthe electroluminescent panel in a front and rear direction of thedisplay, the liquid crystal panel includes a plurality of a liquidcrystal elements; the electroluminescent elements and the liquid crystalelements are aligned with each other in the front and rear direction ofthe display, and at least one of the electroluminescent elements and theliquid crystal elements function as pixels to show an image on thedisplay surface; and the liquid crystal panel being located at the rearof the display surface, and the electroluminescent panel being locatedat the rear of the liquid crystal panel.
 2. The display according toclaim 1, wherein the electroluminescent panel reflects the light thatenters from display surface via the liquid crystal panel.
 3. The displayaccording to claim 1, wherein the display has a liquid crystal operationmode, in which the liquid crystal elements function as pixels, and whenthe display is operating in the liquid crystal operation mode, anelectric field is selectively applied to each liquid crystal elementsuch that the liquid crystal element is selectively switched to alight-transmitting state or a light-blocking state.
 4. The displayaccording to claim 3, wherein, when the display is operating in theliquid crystal operation mode, the electroluminescent elements aremaintained in a light-emitting state or a non-light-emitting state. 5.The display according to claim 3, wherein, when the display is operatingin the liquid crystal operation mode, the electroluminescent elementsare maintained in the non-light-emitting state, and theelectroluminescent panel reflects the light that enters from the displaysurface via the liquid crystal panel.
 6. The display according to claim3, wherein, when the display is operating in the liquid crystaloperation mode, the electroluminescent elements are maintained in thelight emitting state such that the electroluminescent panel functions asa backlight.
 7. The display according to claim 3, wherein, when thedisplay is operating in the liquid crystal operation mode, theelectroluminescent elements are operated in accordance with the liquidcrystal elements such that the electroluminescent element thatcorresponds to the liquid crystal element that is in thelight-transmitting state emits light, and the electroluminescent elementthat corresponds to the liquid crystal element that is in thelight-blocking state does not emit light.